Improvements in sea walls, retaining walls and like structures using pin piles

ABSTRACT

A pin pile is disclosed for anchoring sections of sheet pile to form a wall structure. The pin pile has a casing with a plurality of external clutches formed around the periphery. In use other corresponding clutches on the sections of sheet pile can interlock with the external clutches of the pin pile over a range of angles in accordance with a directional extent of said wall structure.

FIELD OF THE INVENTION

This invention relates to seawalls, retaining walls and like structures.

BACKGROUND TO THE INVENTION

It is well known to drive prefabricated sheet piles into the ground in interlocking fashion to construct a retaining wall or sea wall behind which loose fill such as soil or sand is placed. In order to stabilize and reinforce this fill it is also known to use tie backs in the form of mesh which extend back from the sheet piles into said fill. This diffuses the outward forces that would otherwise act against the back of the pile by causing the fill to stack vertically as opposed to stacking at its natural shallower angle of repose. One disadvantage of such structures however is that the stacked fill causes a large footprint on the surrounding environment behind the wall. The stacked fill for the tie backs also increases construction costs.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to ameliorate the aforementioned disadvantage and accordingly a pin pile is disclosed for anchoring sections of sheet pile to form a wall structure, said pin pile having a casing with a plurality of external clutches formed around the periphery thereof whereby in use other corresponding clutches on said sections of said sheet pile can interlock with the external clutches of the pin pile over a range of angles in accordance with a directional extent of said wall structure.

Preferably said clutches are formed as one piece with the casing and are coextensive with said casing.

It is further preferred that said clutches comprise pairs of male and/or female clutches which slidably engage other corresponding clutches formed on said sheet piles.

It is further preferred that said clutches are spaced to engage said other corresponding clutches which are formed on the inner and outer side flanges of said sheet piles.

It is further preferred that said female clutches comprise slots formed between curved arms with said slots being shaped and sized for a reasonably close tolerance sliding fit over splayed edges of said male clutches.

BRIEF DESCRIPTION OF THE DRAWINGS

One currently preferred embodiment of the invention will now be described with reference to the attached drawings in which:

FIG. 1 is a schematic perspective view of a pin pile for constructing a sea wall, retaining wall or like structure in accordance with said invention,

FIG. 2 is a cross-sectional view of the pin pile of FIG. 1,

FIG. 3 is schematic perspective view of a sheet pile for use with the pin pile of FIGS. 1 and 2 in constructing said sea wall, retaining wall or like structure in accordance with said invention,

FIG. 4 is a cross-sectional view of a sheet pile of FIG. 3, and

FIG. 5 is a plan view of a section of sea wall constructed using pin piles and sheet piles shown in FIGS. 1 to 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring first to FIGS. 1 and 2 the pin pile may comprise a hollow fibre reinforced polymer casing 1 of diameter 300 mm and may be of constant cross-section and indeterminate length depending upon installation requirements. It would be installed typically but not exclusively by driving into soil or fill with an appropriate pile driver. In accordance with the invention a series of external male and female clutches 2, 3 are formed around the periphery of the casing. Other corresponding clutches 2, 3 are also formed on the side flanges of the sheet pile. With the pin pile the clutches extend the full length of the casing. As best shown in FIGS. 2 and 4 the female slots 4 defined within the curved arms 5 of the pin pile clutches and the sheet pile clutches are shaped and sized in cross-section for a reasonably close tolerance sliding fit over the enlarged splayed edges 6 of corresponding male clutches formed on said piles. By virtue of said clutches the pin and sheet piles can be slidably interlocked during installation to form a solid wall structure 7 as shown in FIG. 5. Preferably the pin and sheet piles 1, 8 alternate so that each sheet pile is securely anchored at each end. By using the range of angular positions available around the periphery of the pin pile casing for the clutch connections the wall is readily adapted for installation in curved or angled sections according to terrain requirements. The inward angle of the flanges 8A on which the sheet pile clutches are formed also sets them into the wall structure to protect from damage and provide a protrusion free surface for the wall. Mesh tie backs as normally required with prior art wall structures are avoided by the additional installation of anchor pins 9 (which with this embodiment may comprise rail tracks) driven down through the centres of the pin pile casings into the soil or fill below. In accordance with known practice the interior box sections 10 of the sheet piles and the casings of the pin piles are then infilled with cement or grout to substantially anchor the structure without the requirement of mesh tie backs.

It will thus be appreciated that this invention at least in the form of the embodiment described discloses a novel and improved pin pile for constructing sea walls or the like. Clearly however the example described is only the currently preferred form of the invention and a wide variety of modifications may be made without departing from the scope of the invention. For example while the piles are preferably constructed from a fibre reinforced polymer the invention is not limited to this and any other suitable material such as structural steel may be used. Also the configuration and placement of the clutches on the pin and sheet piles may be changed according to installation requirements or design preference. 

1. A pin pile for anchoring sections of sheet pile to form a wall structure, said pin pile having a casing with a plurality of external clutches formed around the periphery thereof whereby in use other corresponding clutches on said sections of said sheet pile can interlock with the external clutches of the pin pile over a range of angles in accordance with a directional extent of said wall structure.
 2. The pin pile as claimed in claim 1 wherein the external clutches are formed as one piece with said casing.
 3. The pin pile as claimed in claim 1 wherein said external clutches include pairs of male and/or female clutches which slidably engage with said other corresponding clutches on said sections of sheet pile.
 4. The pin pile as claimed in claim 1 wherein said external clutches are spaced to engage said other corresponding clutches which are formed on inner and outer flanges of said sections of sheet pile.
 5. The pin pile as claimed in claim 3 wherein said external female clutches include slots formed between curved arms, said slots being shaped and sized for a sliding fit over splayed edges of said other corresponding male clutches formed on said sections of sheet pile.
 6. The pin pile as claimed in claim 1 wherein said casing is formed from a fibre reinforced polymer.
 7. The pin pile as claimed in claim 1 wherein said external clutches extend the length of the casing.
 8. A wall structure which includes a pin pile having a casing with a plurality of external clutches formed around the periphery thereof and sections of sheet pile with other corresponding clutches which interlock with said external clutches whereby said sections of sheet pile engage said pin pile at selected ones of a range of angles in accordance with a directional extent of said wall structure.
 9. The wall structure as claimed in claim 8 wherein an additional anchor pin is driven down through the centre of the pin pile casing.
 10. The wall structure as claimed in claim 9 wherein said casing is arranged to be infilled with cement or grout in use.
 11. The pin pile as claimed in claim 1 wherein said casing is arranged to be infilled with cement or grout in use. 